Do Now  What causes the seasons?

Objective  State the reasons for global wind patterns and ocean currents.

Coriolis effect: deflection of wind and ocean currents caused by the Earth’s rotation Winds in N. Hemisphere flow to the right Winds in S. Hemisphere flow to the left

jet stream: narrow belt of strong, high speed air height about 10 to 15 km above N. and S. Hemispheres closely related to weather (2) global winds

(current position)

anemometer: instrument that measures wind speed

wind vane: measures wind direction

*always points into the wind wind This is an easterly wind because it is blowing from the east

Doldrums

 Uneven heating of air Uneven heating of air Uneven heating of air  Coriolis Effect Coriolis Effect Coriolis Effect

Ocean Currents  Currents are the steady movement of water in the ocean

Ocean Currents  Currents are the steady movement of water in the ocean surface currents move on or near the surfacesurface currents move on or near the surface

Ocean Currents  Currents are the steady movement of water in the ocean surface currents move on or near the surfacesurface currents move on or near the surface  driven by the wind

Ocean Currents  Currents are the steady movement of water in the ocean surface currents move on or near the surfacesurface currents move on or near the surface  driven by the wind deep currents occur deep beneath the surfacedeep currents occur deep beneath the surface

Ocean Currents  Currents are the steady movement of water in the ocean surface currents move on or near the surfacesurface currents move on or near the surface  driven by the wind deep currents occur deep beneath the surfacedeep currents occur deep beneath the surface  caused by differences in the density of the water

Ocean Currents  Currents are the steady movement of water in the ocean surface currents move on or near the surfacesurface currents move on or near the surface  driven by the wind deep currents occur deep beneath the surfacedeep currents occur deep beneath the surface  caused by differences in the density of the water  move very slowly

Surface Currents  Wind provides energy to move large masses of water

Surface Currents  Wind provides energy to move large masses of water  upper layer of water moves the fastest

Surface Currents  Wind provides energy to move large masses of water  upper layer of water moves the fastest velocity decreases with depthvelocity decreases with depth

Surface Currents  Wind provides energy to move large masses of water  upper layer of water moves the fastest velocity decreases with depthvelocity decreases with depth below 100m most surface currents are undetectablebelow 100m most surface currents are undetectable

Surface Currents  Surface currents are controlled by three factors

Surface Currents  Wind belts

Surface Currents  Wind belts Trade Winds are located just north and south of the equatorTrade Winds are located just north and south of the equator

Surface Currents  Wind belts Trade Winds are located just north and south of the equatorTrade Winds are located just north and south of the equator  push currents westward across tropical latitudes

Surface Currents  Wind belts Trade Winds are located just north and south of the equatorTrade Winds are located just north and south of the equator  push currents westward across tropical latitudes Westerlies are located in the middle latitudesWesterlies are located in the middle latitudes

Surface Currents  Wind belts Trade Winds are located just north and south of the equatorTrade Winds are located just north and south of the equator  push currents westward across tropical latitudes Westerlies are located in the middle latitudesWesterlies are located in the middle latitudes  push eastward in the northern hemisphere

Surface Currents  Wind belts Trade Winds are located just north and south of the equatorTrade Winds are located just north and south of the equator  push currents westward across tropical latitudes Westerlies are located in the middle latitudesWesterlies are located in the middle latitudes  push eastward in the northern hemisphere  in the south, pushes West Wind Drift completely around the world

Surface Currents  Wind belts Trade Winds are located just north and south of the equatorTrade Winds are located just north and south of the equator  push currents westward across tropical latitudes Westerlies are located in the middle latitudesWesterlies are located in the middle latitudes  push eastward in the northern hemisphere  in the south, pushes West Wind Drift completely around the world earth’s largest currentearth’s largest current

westerlies

Surface Currents  Coriolis effect: deflection of the earth’s winds and ocean currents

Surface Currents  Coriolis effect: deflection of the earth’s winds and ocean currents caused by the rotation of the earthcaused by the rotation of the earth

Surface Currents  Coriolis effect: deflection of the earth’s winds and ocean currents caused by the rotation of the earthcaused by the rotation of the earth  Gyres: huge circles of moving water

Surface Currents  Coriolis effect: deflection of the earth’s winds and ocean currents caused by the rotation of the earthcaused by the rotation of the earth  Gyres: huge circles of moving water caused by the combination of wind belts and the coriolis effectcaused by the combination of wind belts and the coriolis effect

Surface Currents  Coriolis effect: deflection of the earth’s winds and ocean currents caused by the rotation of the earthcaused by the rotation of the earth  Gyres: huge circles of moving water caused by the combination of wind belts and the coriolis effectcaused by the combination of wind belts and the coriolis effect clockwise in the northern hemisphereclockwise in the northern hemisphere

Surface Currents  Coriolis effect: deflection of the earth’s winds and ocean currents caused by the rotation of the earthcaused by the rotation of the earth  Gyres: huge circles of moving water caused by the combination of wind belts and the coriolis effectcaused by the combination of wind belts and the coriolis effect clockwise in the northern hemisphereclockwise in the northern hemisphere counterclockwise in the southerncounterclockwise in the southern

Surface Currents  Third factor affecting currents

Surface Currents  Third factor affecting currents continentscontinents

Surface Currents  Third factor affecting currents continentscontinents  deflect and divide currents

Surface Currents  Equatorial currents: westward moving warm-water currents

Surface Currents  Equatorial currents: westward moving warm-water currents Located in all three oceansLocated in all three oceans

Surface Currents  Equatorial currents: westward moving warm-water currents Located in all three oceansLocated in all three oceans  currents in the northern hemisphere

Surface Currents  Equatorial currents: westward moving warm-water currents Located in all three oceansLocated in all three oceans  currents in the northern hemisphere swift warm water moves north in the western side of the oceansswift warm water moves north in the western side of the oceans

Surface Currents  Equatorial currents: westward moving warm-water currents Located in all three oceansLocated in all three oceans  currents in the northern hemisphere swift warm water moves north in the western side of the oceansswift warm water moves north in the western side of the oceans Cool currents move south in the eastern sideCool currents move south in the eastern side

Surface Currents  examples of warm water currents:

Surface Currents  examples of warm water currents: Gulf streamGulf stream

Surface Currents  examples of warm water currents: Gulf streamGulf stream Japan currentJapan current

Surface Currents  examples of warm water currents: Gulf streamGulf stream Japan currentJapan current East Australia currentEast Australia current

Surface Currents  examples of warm water currents: Gulf streamGulf stream Japan currentJapan current East Australia currentEast Australia current Brazil currentBrazil current

Surface Currents  examples of cool water currents:

Surface Currents  examples of cool water currents: West Wind driftWest Wind drift

Surface Currents  examples of cool water currents: West Wind driftWest Wind drift California currentCalifornia current

Surface Currents  examples of cool water currents: West Wind driftWest Wind drift Californa currentCaliforna current Canary currentCanary current

Surface Currents  examples of cool water currents: West Wind driftWest Wind drift California currentCalifornia current Canary currentCanary current Peru currentPeru current

Deep Currents  move more slowly than surface currents

Deep Currents  move more slowly than surface currents  produced as cold, dense water sinks below warmer water

Deep Currents  move more slowly than surface currents  produced as cold, dense water sinks below warmer water from cold polar regions towards the equatorfrom cold polar regions towards the equator denser because of higher salinitydenser because of higher salinity